Multi-position vacuum motor



Jan@ 8, 1963 M. GRIPE MULTI-POSITION VACUUM MOTOR Filed on. 2, 1961United States Patent O 3,072,108 MULTI-POSHN VACUUM MOTOR Maxwell L.Cripe, South Bend, lud., assigner to The Bendix Corporation, South Eend,1nd., a corporation of Eelaware Filed ct. 2, 1961, Ser. No. 142,195 5Claims. (Cl. 121-48) The present invention relates to a vacuum motorcontrol system which will move driven elements from a normal position tomore than one actuated position; and more particularly to a vacuum motorhaving substantially no frictional hysteresis, and an abruptly seatingvalve arrangement which will accurately position the driven elements.

An object of the present invention is the provision of a new andimproved vacuum motor having a normal position and a plurality ofactuated positions which is simple in design, inexpensive tomanufacture, and precise in its operation.

A further object of the present invention is the provision of a new andimproved multi-position vacuum motor of the above described typegenerally comprising a cupshaped housing the open end of which is closedolf by means of a curtain diaphragm structure and which further includesan abruptly closing Valve arrangement for closing olf vacuumcommunication to the motor in at least one of its actuated positions.

The invention resides in certain constructions and combinations andarrangements of parts; and further objects and advantages of theinvention will become apparent to those skilled in the art to which itrelates from the following description of several preferred embodimentsdescribed with reference to the accompanying drawing forming a part ofthis specification, and in which:

FIGURE l is a somewhat schematic view of a multiposition vacuum motorcontrol system embodying principles of the present invention, and inwhich portions are shown in section; and

FIGURE 2 is a somewhat schematic view similar to FIGURE 1 showinganother embodiment of multi-position vacuum motor control system, and inwhich portions are shown in section.

The vacuum motor control system shown in FIGURE 1 is depicted as beingused to actuate a valving structure in the plenum chamber 12 of anautomotive heating system. The plenum chamber 12 is an elongatedstructure having a cross section that is generally a sector of a circle.A heat outlet port 14 is located across the curved section of the plenumchamber adjacent its vertical end wall; and heated air is fed into theplenum chamber through a circular inlet 16 in one end wall of the plenumchamber 12. Valve structure 10 has a circular end portion 18 adapted toslide over and close off the outlet port 14, and an end actuating armportion 2u which overlies the inlet 16 in the end wall of the plenumchamber and is fastened to an actuating shaft 22. The valving structure10 is shown in its off position wherein heat is prevented from enteringthe plenum chamber 12. The heater control shown is also provided with adef-rosting connection 24 in its end wall adjacent the heat inlet 16.The defrosting connection 24 is located to the side of the normalposition of the valving structure 1t) shown in the drawing, and isadapted to be closed off by the end arm 2t) as the valving structure ismoved from the off position, shown, to a car heat position wherein thecircular portion 1S is open with "ice respect to the outlet port 14. Theposition just described wherein the car heat port is open and thedetroster port is closed forms the first actuated position of thevalving structure 10. Valving structure 10 is adapted to be moved intostill a second actuated position spaced clockwise from the rst actuatedposition above described, and wherein both the defrosting connection 24and the heat outlet port 1d are ope-ned. The shaft 22 is rotated bymeans of an arm 26; and the normal, rst actuated position, and secondactuated position of the arm 26 is indicated in the drawings by Offj CarHeat and Defrost, respectively.

The arm 26 is adapted to be moved into each of its three positions bymeans of a Vacuum motor A which in turn is controlled by means of aremotely located valve structure B. The vacuum motor A generallycomprises a cup-shaped housing 3@ having a generally axially extendingintegral chamber 32 which communicates with the open end of thecup-shaped housing 30. The closed or bottom end wall 34 is provided withan axially extending opening 36 therethrough, through which a shaft 38is sealingly guided for reciprocatory motion. The inner end of the shaft38 is suitably fastened to a cup-shaped movable wall 4@ whose sidewalls42 project into the internal chamber 32 and have a generallypredetermined clearance with respect to the sidewalls 44 of the chamber32. The internal chamber 32 is closed off by means of a diaphragm 46.The center portion of diaphragm 46 overlies the movable wall 40, and theouter portion of the diaphragm 46 is sealingly snapped over the radialflange 48 of the housing member 30 adjacent its open end. The diaphragm46 is provided with an annular curtain portion 5d having a generallyU-shaped cross section, the sides of which lie up against the sidewalls42 and 44 respectively. Inward movement of the movable wall 4t?therefore causes one leg of the curtain portion of the diaphragm Sil toroll out of engagement with the sidewalls 42 and into engagement withthe sidewalls 44 of the internal chamber 32. The shaft 38 is providedwith an annular abutment washer 52 suitably aixed to its outer end; andthe abutment washer 52 is normally biased into engagement with the endsurface of the housing 30 by means of a piston return spring 54interpositioned between the movable wall 40 and the inner end wall 34-of the housing member. Reciprocatory motion of the shaft 38 istransmitted to the arm 26 of the heater control structure by means of adrag link 56, the ends of which are suitably pivoted to shaft 38 and arm26 respectively. The shaft 38 and arm 26 are caused to move from theirnormal positions shown ,in the drawing to their first and secondactuated positions by admitting vacuum to the internal chamber 32 of thehousing. These rst and second actuated positions are labeled Heat andDefrost in the drawing.

According to principles of the present invention, the movable wall 4G iscaused to move into, and be held in, a position between its extremeopposite end positions by a valving structure which abruptly closes offvacuum cornmunication to the interal chamber 32 when the movable wall 4@reaches the intermediate or iii-st actuated positie-n. In the embodimentshown in FIGURE 1, vacuum is communicated to the internal chamber 32through a vacuum valve port 58 in the end wall 34 adjacent the shaft 38.The inside surface of the end wall 34 which surrounds the vacuum valveport 58 forms a valve seat against which an annular poppet 61] abuts toclose off the valve port SS.

' Annular poppet 6d may be carried by the shaft 38 in any suitablemanner which will permit the poppet member 60- to be normally positionedat a predetermined location on the shaft 38 and will abut the Wallportions surrounding the valve port 58; and which thereafter will permitthe shaft 38 to move with respect to the poppet member 60 until theshaft 38 reaches its second actuated position. As shown in the drawing,the inner end of the shaft 38 is provided with a reduced diametersection 62 which terminates in a shoulder 64 against which poppet member60 is normally biased by means of the coil spring 66. As shown in thedrawing, the poppet member 60 is generally a cup-shaped member, thebottom end of which abuts the shoulder 64, and the sidewalls 68 of whichsupport the poppet member about shaft 68 and support the coil spring 66.

The second actuated position of the shaft 38 is accurately located bysuitable abutment means conveniently provided by the engagement of theinner end of the sidewalls 42 of the movable wall 40 with the end wall34 of the housing 30. The movable wall 40 is caused to move from itsfirst actuated position to its second actuated position by means of asecond vacuum inlet 70 so arranged that no portion of the vacuum motorwill close olf the inlet 70, and so that vacuum communicated to thechamber l32 through the inlet port 70 will hold the inner edge of thesidewalls 32 in engagement with the bottom 34 of the housing 30. l

Vacuum may be communicated to the ports 58 and 70 by any convenientvalving arrangement that selectively applies vacuum to one of the valveports. One such valve arrangement is shown at B and is formed by meansof a valve housing 80 having a longitudinal bore 82 therethrough whichis sealingly engaged by a valve slidel 84. Vacuum is communicated to thelongitudinal bore 82 through a vacuum inlet '86 located in the centersection of the bore 82. The second vacuum inlet 70 of the motor A isconnected to the bore 82 adjacent one end thereof, through the valveport 88; and the valve port 58 of the motor A is connected to the bore82 by means of a valve port 90 positioned between the valve ports 86 and88. The valve slide 84 is provided with a reduced diameter section 92adjacent its center section, and the reduced section 92 is of such alength as to be capable of overlying all three vacuum ports 86, 88 and90. The outer end of the. valve slide 84 at all times closes off theouter end of the bore 82; and the land portion 94 of the slide formedinwardly of the reduced diameter section 92 is of such a length as tocover only the valve port 90 when the inner end of the reduced diametersection 92 just overlies the vacuum inlet connection 86. The inne-r endvof the shaft 84 also has a reduced diameter section 96 to allow air toenter the valve port 88 in the Off position of the slide 84, shown inthe drawing. A suitable stop 98 is provided on the end of the valveslide 84 to prevent withdrawal of the slide 84 beyond the above referredto Off position.

In the normal Off position of the slide 84 above referred to, the vacuumfrom the inlet port 86 of the valve structure B is prevented from beingcommunicated with either of the valve ports 88 or 90; while atmosphericpressure is communicated to the valve port -88 and hence to the inletchamber 32 of the vacuum motor A tocause its kmovable wall 40 and shaft38, under the action of the return spring 54, to move to the Oliposition shown in the drawing. By forcing the valve slide 84'inwardlyuntil the land portion 94 moves out of registry with the valve port 90,vacuum is communicated to the motor inlet port 58 causing-airprcssure'on the diaphragm 46 to move the movable wall 40 inwardly untilthe poppet member 60 abuts the end wall 34 and 'closes off furthervacuum communication through the inlet port 58. Inasmuch as the controlvalve B is of the 4slide valve type, and inasmuch as a sliding tit isdepended upon between the shaft 38 and the motor housing 30, a slightamount of air leakage occurs which enters the internal chamber 32 of thehousing 30 and is throttled out through the valve port 58 by a veryslight reciprocatory movement of the shaft 38. Inasmuch as substantiallyno sliding friction is involved in the rolling action of the diaphragm46, substantially no further movement of the shaft 38 takes place afterthe poppet 60 closes off the inlet port S8; and the slight amount of airleakage above referred to assures that the shaft 38 will be maintainedin the iirst actuated position above described.

When it is desired to move the arm 26 into its second actuated position,the valve slide 84 is moved inwardly until its land portion 94communicates vacuum from the inlet port 86 with the valve port 88;whereupon full vacuum is communicated to the internal chamber 32 of thevacuum motor A, and the end surface of the sidewalls 42 of the movablewall 40 are moved into and held in positive engagement with the bottomend 34 of its housing 30.

The -return movement of the arm 26 to the Off position is produced bythe piston return spring 54 which has suficient force to overcome thefriction involved. The valve slide 84 is pulled to its extreme outposition, wherein atmospheric vpressure is communicated to the valve.port 88 to in turn allow air pressure to enter the internal charnber 32and cause the movable wall 40 under the action 0f its return spring 54to move to its normal position. Thereafter the movable wall 40 can becaused to move into its irst actuated position in the manner previouslydescribed.

The embodiment of vacuum motor control system shown in FIGURE 2corresponds, generally, in construction and `operation tothe systemshown in FIGURE l; but differs principally therefrom in the constructionof the valving arrangement within the vacuum motor that is used to holdthe motor in its first actuated position. The system also differs in theconstruction of the remotely located valve structure that is used togovern the operation of the vacuum motor. Those portions of FIGURLE 2which correspond generally to similar portions of FIG- URE l aredesignated by a like reference numeral characterized further in that aprime mark is aiixed thereto.

In the embodiment shown in FIGURE 2., the vacuum valve port 58 is causedto enter the `axially extending opening 36' which receives the shaft 38adjacent the internal chamber 32' of the vacuum motor A. The shaft 38has va shoulder 100 formed by a reduced diameter section 102, and is solocated as to close off the end of the opening 36' in the firstactuated'position ofthe motor. The inner end 104 of the shaft 38 is ofthe same diameter as the 'outer end so as to eect a sliding seal withrespect to the bore 36, and so permit movement from the first actuatedposition of the motor to the second actuated position of the motor,wherein the inner end of the sidewalls 42 also engage the bottom of theend wall 34 Vof the housing 30.

In the embodiment of control valve structure -B shown in FIGURE 2, thevacuum inlet enters the longitudinal bore 82 between the valve Iports 86and '88. The valve slide 84 has va center land portion 06 which closesoff the vacuum port 90 in the normal Oli position shown in the drawing;and has inner and outer reduced diameter sections 108 and "ill-0 whichare adapted to communicate ports 88 and 90', and 98' and-86respectively. The inner end of the slide 84 is provided with alandportion 112 adapted to prevent atmospheric pressure from entering theport 88 in the normal Off position of the slide shown in the drawing.The outer end of the slide 84 is also provided with a similar land 114adapted to prevent atmospheric communication with the valve port 86 inthe normal Off position of the slide shown in the drawing. Inwardmovement of the slide 84 from the position shown in the drawingcommunicates vacuum from the port 90" to the port 86, and hence theinternal chamber 32', to cause the movable Wall 40 to move into itsFirst Actuated position wherein the land E06 just seals off the innerend of the shaft opening 36. The throttling action thereafter maintainsthe movable wall in its First Actuated position in substantially thesame manner described for the embodiment of FIGURE l. Outward movementof the slide 84 from the Off position shown in the drawing communicatesvacuum from the inlet 90 to the port 88 to cause the movable wall 40' tomove until it engages the end wall 34. Extreme outward movement of theslide 84 communicates atmospheric pressure with the valve port 88 toallow the return spring 54 to move the structure to the normal Offposition shown in the drawings. A suitable friction spring 116 isprovided in the slide 84' to hold it in its various positions.

It will be apparent that the objects heretofore enumerated as well asothers have been accomplished; and that there has been provided animproved vacuum motor of inexpensive construction having generallyfrictionless operation, and which can accurately be positioned through`an internal positive valving arrangement by a simple remotely locatedvalve structure.

While the invention has been described in considerable detail, I do notwish to be limited to the particular ernbodiments shown and described;and it is my intention to cover hereby all novel adaptations,modifications and arrangements thereof which come within the practice ofthose skilled in the art to which the invention relates.

I claim:

1. In a vacuum motor control system: a cup-shaped housing having agenerally closed bottom end wall and an internal chamber openingoutwardly of the open end of said cup-shaped housing; a movable wall insaid internal chamber, the sides of said movable wall having apredetermined clearance with respect to the sidewalls of said internalchamber; a curtain diaphragm overlying said movable wall with a rollingU-shaped portion extending into said predetermined clearance to rollbetween the sidewalls of said chamber and the surface of said movablewall during movement of said movable wall, and its outer edge sealinglyfixed to the sidewalls of said housing; a driven shaft extending throughsaid end wall of said housing and operatively connected to said movablewall; means biasing said movable wall to a normal position adjacent theopen end of said internal chamber; a first vacuum valve port in the endwall of said internal chamber adjacent said shaft; valve shut-off meanscarried by said shaft for closing said vacuum valve port when saidmovable wall moves from its normal position inwardly to a first actuatedposition; abutment means limiting inward movement of said movable wallto a second actuated position wherein said movable wall is spacedinwardly from said first actuated position; a second vacuum port openinginto said internal chamber and which is not closed off by said movablewall; said valve shut-off means remaining closed as said movable wallmoves from said first actuated position to said second actuatedposition; and valve means for selectively applying vacuum to respectivefirst and second valve ports.

2. In a vacuum motor `control system: a cup-shaped housing having agenerally closed bottom end wall and an internal chamber openingoutwardly of the open end of said cup-shaped housing; a movable wall insaid internal chamber, the sides of said movable wall having apredetermined clearance with respect to the sidewalls of said internalchamber; a curtain disphragm overlying said movable wall with a rollingU-shaped portion extending into said predetermined clearance to rollbetween the sidewalls of said chamber and the surface of said movablewall during movement of said movable wall, and its outer edge sealinglyfixed to the sidewalls of said housing; la driven shaft extendingthrough said end wall of said housing and operatively connected to saidmovable wall; means biasing said movable wall to a normal positionadjacent the open end of said internal chamber; a first vacuum valveport in the end wall of said internal chamber adjacent said shaft; saidshaft having an outwardly facing shoulder positioned in said internalchamber with a reduced diameter section of said shaft positionedoutwardly of said shoulder; a valve closure member spring biasedinwardly against said shoulder for closing off said first vacuum valveport when said movable wall is in its first actuated position, saidvalve closure member being slidable outwardly on said shaft; abutmentmeans limiting inward movement of said movable wall to a second actuatedposition wherein said movable wall is spaced inwardly from said firstactuated position; a second Vacuum port opening into said internalchamber and which is not closed off by said movable wall; said valveshut-off means remaining `closed as said movable wall moves from saidfirst actuated position to said second actuated position; and valvemeans for selectively applying vacuum to respective first and secondvacuum ports.

3. In a vacuum motor control system: a cup-shaped housing having agenerally closed bottom end wall and an internal chamber openingoutwardly of the open end of said cup-shaped housing; a movable wall insaid internal chamber, the sides of said movable wall having apredetermined clearance with respect to the sidewalls of said internalchamber; a curtain diaphragm overlying said movable Wall with a rollingU-shaped portion extending into said predetermined clearance to rollbetween the sidewalls of said chamber and the surface of said. movablewall during movement of said movable wall, and its outer edge sealinglyfixed to the sidewalls of said housing; an opening through said endwall; a driven shaft extending through said opening in said end wall ofsaid housing and operatively connected to said movable wall; meansbiasing said movable wall to a normal position adjacent the open end ofsaid internal chamber; a first vacuum valve port in the sidewalls ofsaid opening in the end wall of said internal chamber adjacent saidshaft; said shaft having a reduced diameter section with an outersection of said shaft adapted to slide into and close off said openingin said end wall when said movable wall is in a first actuated positionspaced inwardly from said normal position; abutment means limitinginward movement of said movable wall to a second actuated positionwherein said movable wall is spaced inwardly from said first actuatedposition; a second vacuum port opening into said internal chamber andwhich is not closed off by said movable wall; said valve shut-off meansremaining closed as said movable wall moves from said first actuatedposition to said second actuated position; and valve means forselectively applying vacuum to respective first and second vacuum ports.

4. ln a vacuum motor control system: a housing having an internalchamber; a movable wall in said chamber; a curtain diaphragm overlyingsaid movable wall, said diaphragm having its outer edge fixed tothesidewalls of said housing; a driven shaft projecting from saidhousing and operatively connected to said movable wall; means biasingsaid movable wall to a normal position adjacent an end of said internalchamber; a first vacuum valve port in said housing leading to saidinternal chamber; valve shut-off means carried by said shaft for closingsaid first vacuum valve port when said movable wall moves to a firstactuated position; abutment means limiting inward movement of saidmovable wall to a second actuated position spaced from said firstactuated position; a second vacuum port opening into said internalchamber, which second valve port is open to said chamber regardless ofthe position of said movable wall; and valve means for selectivelyapplying vacuum to respective first and second valve ports.

5 ln a vacuum motor control system: a housing having an internalchamber; a movable wall in said internal chamber, the sides of saidmovable wall having a predetermined clearance with respect to thesidewalls of said internal chamber; a curtain diaphragm overlying saidmovable wall, said diaphragm having its outer edge sealingly fixed tothe sidewalls of said housing; a driven shaft projecting from saidhousing and operatively connected to said movable wall, said shafthaving an outwardly facing shoulder positioned in "said internal chamberwith a reduced diameter section of said shaft positioned outwardly ofsaid shoulder; Vmeans biasing said movable wall to a normal positionadjacent the open end of said internal chamber; a first vacuum valveport in said housing leading to said internal chamber; a valve closuremember spring biased to abut with said shoulder of said shaft forclosing oit said rst vacuum valve port when said movable wall is in itsrst actuated position, said valve closure member being slidableoutwardly on said shaft; abutment means limiting inward movement of saidmovable wall to a second actuated position wherein said movable wall isspaced inwardly from said ust actuated position; a second vac- 8 u'umport opening into said internal chamber land which is not closed olf bysaid movable wall; and valve means for selectively applying vacuum torespective rst and second vacuum ports.

References Cited in the tile of this patent UNITED STATES PATENTS2,134,072 Christensen Oct. 25, 1938 2,465,714 Elliott Mar. 29, 19492,854,954 Howze Oct. 7, 1958 2,895,455 Clowes July 21, 1959 2,986,125Young et A'al May 30, 1961

1. IN A VACUUM MOTOR CONTROL SYSTEM: A CUP-SHAPED HOUSING HAVING AGENERALLY CLOSED BOTTOM END WALL AND AN INTERNAL CHAMBER OPENINGOUTWARDLY OF THE OPEN END OF SAID CUP-SHAPED HOUSING; A MOVABLE WALL INSAID INTERNAL CHAMBER, THE SIDES OF SAID MOVABLE WALL HAVING APREDETERMINED CLEARANCE WITH RESPECT TO THE SIDEWALLS OF SAID INTERNALCHAMBER; A CURTAIN DIAPHRAGM OVERLYING SAID MOVABLE WALL WITH A ROLLINGU-SHAPED PORTION EXTENDING INTO SAID PREDETERMINED CLEARANCE TO ROLLBETWEEN THE SIDEWALLS OF SAID CHAMBER AND THE SURFACE OF SAID MOVABLEWALL DURING MOVEMENT OF SAID MOVABLE WALL, AND ITS OUTER EDGE SEALINGLYFIXED TO THE SIDEWALLS OF SAID HOUSING; A DRIVEN SHAFT EXTENDING THROUGHSAID END WALL OF SAID HOUSING AND OPERATIVELY CONNECTED TO SAID MOVABLEWALL; MEANS BIASING SAID MOVABLE WALL TO A NORMAL POSITION ADJACENT THEOPEN END OF SAID INTERNAL CHAMBER; A FIRST VACUUM VALVE PORT IN THE ENDWALL OF SAID INTERNAL CHAMBER ADJACENT SAID SHAFT; VALVE SHUT-OFF MEANSCARRIED BY SAID SHAFT FOR CLOSING SAID VACUUM VALVE PORT WHEN SAIDMOVABLE WALL MOVES FROM ITS NORMAL POSITION INWARDLY TO A FIRST ACTUATEDPOSITION; ABUTMENT MEANS LIMITING INWARD MOVEMENT OF SAID MOVABLE WALLTO A SECOND ACTUATED POSITION WHEREIN SAID MOVABLE WALL IS SPACEDINWARDLY FROM SAID FIRST ACTUATED POSITION; A SECOND VACUUM PORT OPENINGINTO SAID INTERNAL CHAMBER AND WHICH IS NOT CLOSED OFF BY SAID MOVABLEWALL; SAID VALVE SHUT-OFF MEANS REMAINING CLOSED AS SAID MOVABLE WALLMOVES FROM SAID FIRST ACTUATED POSITION TO SAID SECOND ACTUATEDPOSITION; AND VALVE MEANS FOR SELECTIVELY APPLYING VACUUM TO RESPONSIVEFIRST AND SECOND VALVE PORTS.